HIV2 chronic infection of promonocytic cells

HIV1 infection of mononuclear phagocytes is now well established, whereas HIV2 infection of these cells is less well documented. In this work, we studied the replication of the HIV2ROD strain in the U-937 promonocytic cell line and compared it with that of the HIV1BRU strain. p24 antigen and RT (reverse transcriptase) activity were assessed at regular intervals in cell-free supernatants, as was the infectiousness of the produced virus. In the case of HIV2, after a phase of high cell mortality, a chronically infected cell population releasing infectious virions was obtained (the infection remained stable after 60 days of culture). By contrast, for a given multiplicity of infection (i.e. 10,000 cpm RT/10(6) cells), HIV1 replication in U-937 cells was only transient (i.e. 14 days), leading to the synthesis of slightly infectious and probably defective viral particles. Abortive infection was finally obtained, as confirmed by a polymerase chain reaction which failed to detect any proviral HIV1 DNA in the cell line. These results indicate a marked difference between HIV1 and HIV2 in their in vitro interaction with mononuclear phagocytes.